Vice President Mike Pence has been offering some reassurance to Eastern European countries this week. He's wrapping up a trip to Estonia, Georgia and Montenegro, some of the countries that feel most threatened by Russia. NPR's Tamara Keith reports.

TAMARA KEITH, BYLINE: Any visit by someone as high-ranking as the vice president to these particular countries isn't an accident; it's a signal. Estonia, Georgia and Montenegro now find themselves looking over their shoulders at Russia as it moves to reassert and expand its influence and control. On each stop, Vice President Pence's basic message has been the same.

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VICE PRESIDENT MIKE PENCE: President of the United States of America, President Donald Trump, sent me here with a simple message for you and for the people of Georgia. We are with you.

KEITH: It matters because the Trump administration's commitment to the NATO alliance and its all-for-one-and-one-for-all defense policy hasn't always been totally clear. Georgia isn't a member of NATO, but Pence reaffirmed a long-held U.S. position of supporting its desire to join. Estonia is a member and, in just the last couple of days, had NATO warplanes shooing off Russian jets over its airspace.

And tiny Montenegro, where Pence landed yesterday, is the newest member of the alliance.

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PENCE: Let me assure you, I am here as a testament to the fact that America has no small allies, only strong allies. And I hope my presence here today affirms that.

KEITH: When Russia hailed president Trump's election, this probably isn't what it had in mind. Evelyn Farkas is a senior fellow at The Atlantic Council, who, in the Obama administration, worked on Russia policy at the Defense Department.

EVELYN FARKAS: The reality is up to this point, nothing has changed with regard to how the United States is managing the relationship with Russia in a concrete sense. So we are continuing all of the deterrence measures that we developed under the Obama administration. In fact, the deterrence is getting stronger, if anything.

KEITH: Pence's trip comes at a dismal moment in U.S.-Russia relations. Congress passed bipartisan legislation imposing tough new sanctions on Russia and limiting the president's ability to relax sanctions on his own. The White House says President Trump plans to sign it. Then over the weekend, Russian President Vladimir Putin said the U.S. has to reduce its staff in Russia by 755 positions.

Trump has been silent on that. But both Secretary of State Rex Tillerson and Pence responded yesterday.

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PENCE: We hope for better days. And we hope for better relations with Russia. But the recent diplomatic action taken by Moscow, I can assure you, will not deter the commitment of the United States to our security, that of our allies and to freedom-loving nations around the world.

KEITH: This isn't Pence's first trip overseas talking up the U.S. commitment to NATO's mutual defense clause. And President Trump has recently said in strong terms that he supports it too. But back in May on Trump's first foreign trip as president, he went to NATO headquarters and left affirming the commitment out of his speech.

Julianne Smith is the director of the Transatlantic Security Program at the Center for a New American Security.

JULIANNE SMITH: Of course the vice president begins every sentence by stating that he is bringing a direct message from the president. But as I talk to friends in these countries, there is skepticism as to whether or not the entire White House stands behind what the vice president is indeed saying.